DESCRIPTION (provided by applicant: The HIV/AIDS pandemic has had a devastating global impact causing more than 30 million HIV-1 infections and over 25 million deaths worldwide. In addition, it is estimated that annually over 450,000 infants are infected through mother-to-child transmission (MTCT). Although antiretroviral therapy (ART) is effective to save lives and reduce MTCT, the coverage of ART in treatment-eligible patients in developing countries is only approximately 67% due to the lack of simple, inexpensive and rapid near-patient treatment monitoring tools. To address the unmet need, we propose to develop an HIV-1 viral load monitoring microfluidic platform technology development of a sensitive photonic crystal sensing technology. This technology detects and quantifies the binding of biotargets (e.g., HIV-1 virus particles) to an optical sensing surface due to the change of bulk index of refraction. The resulted shift in the peak wavelength value correlates with the concentration of biotargets in a biological sample. This technology- driven proposal addresses a significant global clinical need and aims to deliver a portable photonic crystal device that can (i) selectively capture HIV-1 from whole blood, (ii) be sensitive within the clinical cut-off (with 10% error range), inexpensive (<$1), rapid (within 30 minutes), and (iii) handle fingerprick whole blood (up to 100 L) to aid i HIV patient care and treatment in resource-constrained settings. The delivery of this photonic crystal-based HIV-1 viral load monitoring microchips can significantly facilitate the expansion of ART in developing countries, achieving universal access to ART to control the AIDS pandemic.